3) Check After Engine Failure; 1) Engine Runs Erratic And Misfires; 2) Unintended Engine Stoppage By Seizing; 3) Engine Back To Operation After Submerging In Water - Rotax 914 F Maintenance Manual

12.4.3) Check after engine failure

After a failure it is important to communicate all details available to the
authorized workshop. Also observations on the aircraft and the engine
suspension can be of help. To ease diagnosis of the failure, pay special
attention of the engine behaviour described below:

12.4.3.1) Engine runs erratic and misfires

May be caused by a failure in the fuel system (fuel supply, contamination, float
chamber venting, false air intake due to defective carburetor flange, carbure-
tor icing), or in the ignition system (shorting cable, electronic module, spark
plugs, wrong spark plug connection, grounding defect etc.). See details
regarding fuel- and ignition system.

12.4.3.2) Unintended engine stoppage by seizing

A failure in the lubricating system may be the cause. Oil pressure too low or
no oil pressure due to oil shortage, contamination or bad venting of the oil
system, defect in the oil pump. As a consequent damage, often the camshaft
and/or the conrod bearings are seized. Carry out complete tear-down inspec-
tion and repair. See details regarding lubrication system.

12.4.3.3) Engine back to operation after submerging in water

An engine having submerged in water has to be sent immediately for
overhaul to an authorized overhaul facility. See Chapter 14.4).

12.4.4) Rough engine run

Either a failure of the ignition system or in the carburetor may be the reason
(fuel supply, contamination in float chamber or float needle valve, float
chamber venting, false air intake due to defective carburetor flange, engine
temperature too low, too lean carburetor jetting due to conditions prevailing
in intake silencer). See details regarding fuel- and cooling system.

12.4.5) Checks for extreme climatic conditions

Flying in deserts or areas with heavily contaminated or dusty air causes
increased wear of all components. Therefore shorter maintenance intervals
are recommended.
Flying in areas of extreme climatic conditions or in extreme altitudes requires
correction of carburetor jetting and of the cooling system. This requires
consultation with the engine manufacturer.
Modification no.
- 0 -
WARNING: If one of the above failures should arise even only for a short
time, an exact engine check is necessary. Localize trouble
and rectify.
ATTENTION: The engine must be marked clearly with the note: "Engine
submerged in water during operation".
WARNING: More frequent checks of air filter, coolant radiator and oil
cooler are necessary.
Reference Main Date
914 F 1997 02 01
Page
115